1. Field of the Invention
The present invention relates to polycarbonate compositions (PC compositions) which, in composite components, have an improved adhesive bond in direct contact (without primer) with polyurethane-based components, such as, for example, lacquers, hard or soft solid coatings or foams, and the composite components and a process for their production. In this context, the polyurethane layer can serve, for example, to improve the surface properties, the haptic properties, the visual properties and the noise and heat insulation of the composite components.
2. Description of Related Art
In particular in a composite with polyurethane-based lacquers, preferably water-based lacquer systems, the compositions according to the invention have an improved lacquer adhesion. Preferred compositions according to the invention furthermore have a combination of high E modulus, high heat distortion temperature, low and largely isotropic coefficients of thermal expansion, low shrinkage during processing and high melt flowability and are particularly preferably suitable in this respect for production of large-area lacquered automobile body components.
The application of polyurethane-based layers to supports of polycarbonate compositions is known in principle from the prior art, and in the case of impact-modified polycarbonate compositions reinforced with minerals, which are employed for the production of large-area automobile body components with high demands on toughness, rigidity and dimensional accuracy, in general require, however, the additional application of a primer, i.e. an adhesion-promoting primer layer, to achieve an adequate adhesive bond.
In the course of an inexpensive and also ecologically favourable production of components, it is desirable, especially on the part of the automobile industry, to provide polycarbonate compositions which, in composite components, have an improved and therefore adequate adhesive bond in direct contact with polyurethane-based layers, i.e. also without an adhesion-promoting primer intermediate layer.
EP 1355988 A1 describes polycarbonate compositions containing aromatic polycarbonate, inorganic material of anisotropic particle geometry, preferably talc, rubber-modified vinyl (co)polymer and one or more components chosen from the group of thermoplastic rubber-free vinyl (co)polymers and polyalkylene terephthalates. However, the application makes no references at all to the advantages of such compositions with a particular ratio of polycarbonate, polyalkylene terephthalate and vinyl (co)polymer with respect to lacquer adhesion.